Numerous progressive lenses are known in the prior art. Progressive lenses are typically designed to have distance, near and intermediate viewing zones where the intermediate zone joins the near and distance zones in a cosmetically acceptable way, such that no discontinuities in the lens are visible to people observing the wearer.
Significant advances in customising progressive lens design have been disclosed in international patent application PCT/EP97/00105. This application describes a series of lens elements where the progressive designs vary depending on whether the wearer is a myope (short-sighted), emmetrope (normal vision) or hyperope (long sighted), whilst maintaining substantially constant the optical field of vision in the near and/or distance zones.
Whilst these designs are a significant advance, they do not vary with the specific optical requirements of the individual wearer. For example, the designs do not vary when an astigmatic correction is introduced to the back surface of the lens.
It is an object of the present invention to provide a progressive ophthalmic lens that compensates for optical corrections introduced for individual wearers.